Safety release device for tanks



Sept. 16, 1958 D. A. KIFFER ETAL 2,852,169

SAFETY RELEASE DEVICE FOR TANKS Filed Sept. 26, 1955 2 Sheets-Sheet 1llllllili- AWHZ UPE A 5/85 A. AIFFER ZAWRENCE 0 255;

Sept. 16, 1958 D. A. KIFFER ET AL 2,852,169

SAFETY RELEASE DEVICE FOR TANKS Filed Sept. 26, 1955 2 Sheets-Sheet 20/2. K M 3 :H S L F E 1 7 45 W T D U M E5 w Fm T. W ,0 A 5 Z 3 partlybroken'of ap'ortiornof-the'spraytank "illustrating the instantinvention;

United States PatentO SAFETY RELEASE DEVICE FOR TANKS -Desire A;Kilfer," Waterlooyandliiawrence DI-Ors'er,

Cedar Falls,ilowa,'assignors to. Ghainberlain Corporation,Waterloo,rlowa, a-corporation of Iowa .Application September 26,".1955,Serial No. 536,423

.- 8 Claims. (Cl.:-2 22-;-. 396) on a flame sprayer or weed burner, itobviously can be .used on other spray tanks and on many otherftypes ofpressure tanks.

-Heretofore, in the usefof flame sprayers having a spray tank, it wassometimes a hazardous operation inasmuch as a lackadaisical user,insteadr otbuildingupthepressure in the spray tankicontainingw theinflammable liquid by use of the-usual hand pumpgdirectedithelflame fromthe burner jagainst the sidejofsthe tank toincrease' the pressure byraising the. temperature 'of..the..inflammable 1iquid; Such amethodiofraising-[the .tank pressure is dangerousin that extreme. pressure is.built up in a short 7 .period of time which cannot be withstood by..the.tank

thereby causing the spray tankto blow..up,..and.in the past this hascaused grave. injuryandsometimes death to a. user. 7

T In the present invent-ion, a safety release device is.associated witha spray tankwhichperrnits the top. or cover of the spray tank to raiseup when a. predetermined pressure isdeveloped in the tank and.a1l0w.;the excess of i that pressure to escape' Under actual tests, itwas. found impossible. to blow-up a spraytankrequipped with:.this

device.

' Accordingly, it is an objectofthis inventionv to.pro-

vide an. improved spray tank for handling..inflammable liquids that willnot blow up under any. circumstances.

Another object of this invention is to provide a safety 1 release devicefor pressure tanks that isefiective. torelieve against, extremely suddenvariationsin,pressure-. as well as steady pressure rises.

A further object of this invention. residesin .the. provision of a.spray tank. havingmeans topermit'the top or coverof the .tank to raisenpwhen a predetermined pressure is, developed in. thetankand allow .theexcess of that pressure to escape.

. Afurther feature ofthis invention is. toprovide asafety release deviceforuse. on spray. tanks. and to-bemounted .inthe top lockassembly. thatdoesnot. occupy any. notice- ,ableadditionalspace over. and abovethespace. required .forconYentionaLtop lock assemblies heretofore.

While someofthe. more. salient features, ..characteris- .tics... andadvantages ofthe. instant. inventionhave. been .above pointed out,.others willabecome apparent from the .following disclosures,.takeninconjunction with the accompanying drawings, in-which:

- .Figure lis a; broken elevationalview of a flamesprayer equipped withthe present invention;

' Figure 2 is' an elevational view,- partly; in section .and in'Figure 1Patented Sept. 16, 1958 ice "Figure 3 is atop plan view ofthe spraytankwith the cover assembly and burner. assembly removed. therefrom; and

"Figure 4 is a top plan view'of thejpurnp handle locking :means, takensubstantially along' linein? Figure 2 and looking in the directionofithe arrows.

As shown on the drawings; Referring generallyqtoi'lf'figuree l, af'flame .sprayer equipped with the present invention is" illustrated com-.prisinggenerally a conventional cylindrical- ,tank ;10, a

-. conventional burner/assembly 11 connected to the ,tank

'10 by a flexible tubing'.11a,.a'nd aacover assemblyin inwhich ismounted. the Isafetyrelease m'echanismfofi the v. instant invention. e

. A'strap. assembly 13 is: connected. al'.=,0n6..1id near. .the top ofthe tank'ltl'and at the other end near the,,bottom thereof for:facilitating. transporting, of: the .sprayeizl'from placetoplace.

iThevt'ank 10 is closed. atone end. and initially. open at. theother..end.befoIeJfinaLaSsembIy.. .Ahead 14 is sealingly secured, suchasby weldingorother' equivalent means to the open end oi the tank' 10.

As seen most clearly in Figure'Z, the head..14 is. in

....the,general .form. of .an. annulus. having .a radially inwardly...ex tendingrflange 15..l.Before the flangef-li. is rolled, a

., ,camring. -16... havingsan annular. 'flange portion- 16a is,spoLw'eldedto the. head. flhensthefiangerli is..rolled ...over the 3upper: surface. and .ma'rginal Ledge. ofsthesflange .portion 16a..zAsi'seen in:Eigure2nan openingl4a is .prov-ided: in. the. head 14foraconnection ';to.. the. burneras- ...sembly.

..:C.onnecting vwith. theannular.portionlfia. of; the...carn

,ring .16, is a substantially. vertical. cylindricalportion.:16b

. ing section 16c.

which, in turn, merges with achannel-shaped coverv lock- The upper legofthechannel-shaped section-16c. is. .bayonet slotted ;at. 16d asaseenn.in Eigure 3,. and the-sections of the legbetween the slots are slightly7 inclined;- from. one end :of .the..section.:to. theuothercendtovprovide aconvent-ionalcammingarrangement.

.The..coverassembly; 12 includes a dishashaped. lid. 17

. having an annular. lip18 connected .to. the. uppermarginal .-.edge.and.sized. to.be substantially..diametrally'larger than sthemfiange- 15.vAv ring-shaped .gasket. or. seal .19 of any suitableresilient..material. iswfitted on vthe. underside. of

.zthe .;lip ,18 .toaccommodate. sea-ling..engagemenhbetween .The.dishshaped did. 17 iscentrally; apertured :and. pro- ,vided .with anupturned annular flange; 17a "for.v receiving a -pumping. cylinderlll.The. pumping cylinder-20pxtends downwardly into the tank and is providedat. its

.bottom end with a. unidirectional valve .(not.-sho.vvn) to :al-lowairflow into thetank. Theupperv end of the pumpa ing cylinderldextendsslightly; above the flange opening -in .thelid 17 and terminates inamollededge, andcylinder. 20. issealingly-secured tothefiange17a-of:.the:lid

.- 17 .in asuitable manner, such. as by welding.

"To. secure the: lid in. position, a. lid locking assembly '-or yokeincludes a sleeve 21 having a pair ot'diametrically the camring 16. a Y

opposed arms-22, .22, .the ends ofwhich are received, by

.As seenrin Figure 2;.the sleeve-.21;--.is centrally-bored and receivesinrthreaded engagement 1 at 23 a pump dock -.and sealing screw 24.The-.sleeveabore is diametrically enlarged at 21a and the sealing screw24 iss'diametrically reduced at;the lowerportionasindic-ated at 24a: todefine :g-an annular. chamberwor socket for-:-'receiving az-he'avy metal1 helical-spring :25.

'lrhe springr25 surrounds zthenreduced: 'portion' 24a of :theilsealingscrew 24 and is bottomed on aneannular shoulder 'of' the: sealing screw-24 provided by'- the i diametrally reducedsection and indicatd =-at24b. The

other end of the spring is bottomed on a centrally apertured dome-shapedmember 26 that is received over the extreme end of the sealing screw 24.The domeshaped member 26 functions as a pump cap and is maintained onthe end of the sealing screw 24 by awasher 27 abutting against theunderside of the cap, and which is held in place onthe reduced end ofthe sealing screw 24 by a retaining ring 28.

The force of the spring 25 is transmitted to the lid 17 through anannular flange 26a on the dome-shaped pump cap 26, and the force of thespring urges the lid 17 into sealing engagement with the flanged openingof the tank 10.

To maintain the lid 17 and pump cylinder 20 connected to the sleeve 21and locking arms 22, a series of lugs 29 are annularly arranged andcarried on the inner face of the pump cap 26 and near the lower marginaledge thereof to coact with the upper rolled edge of the pump cylinder 20when removing the entire assembly from the tank 10.

To initially build the pressure up within the tank a hand pump isprovided having a pump rod or shaft 30 slidably received in a centralbore of the sealing screw 24. A plunger 31 is connected to one end ofthe shaft 30 and operable within the pump cylinder 29, and a pump handle32 is connected to the other end, as seen in Figure 1.

To lock the pump handle in place on the cover assembly 12, a pair ofdiametrally opposed pump locking arms 33, 33 are suitably secured to thepump handle 32 and coact with a pump locking ring 34 on the sealingscrew member 24. As seen most clearly in Figure 4, the pump locking ring34 is provided with a pair of diametrally opposed slots 35, 35 forreceiving the locking arms 33. The handle is locked in position bypushing down the locking arms 33 through the slots 35 and turning thehandle so that the inwardly extending lugs 33a on the locking arms arepositioned away from the slot 35. A pair of diametrally opposed lugs 36,36 extend outwardly from the locking ring 34 and are in arcuately spacedrelationship to the slots 35. These lugs provide abutments or stops forthe locking arms 33 on the pump handle 32. To maintain the locking arm33 on the handle 32 in tight engagement with a locking ring 34, a spring37 surrounds the pump shaft 30 and is received in a shallow grooveformed around the shaft in the sealing screw 24. The spring is bottomedin the groove at one end and engages the handle at the other end.

In the initial assembly of the cover arrangement 12, the spring 25 ispreloaded to a predetermined amount to urge the lid 17 in sealingengagement with the tank flange 15. Additional loading of the spring 25may be accomplished by turning the sealing screw member 24 down into thesleeve 21.

In operation, after the cover assembly 12 has been placed in lockingengagement with the head 14 of the tank 10, pressure is initially builtup within the tank against the inflammable or other liquid therein bythe hand pump. If the user, in order to raise the pressure in the tank,directs the flame of the burner against the side of the tank, and thepressure rises above a predetermined amount, the lid 17 will raiseagainst the force of the spring 25 and break the seal with the flange 15to allow the excess pressure to escape from the tank.

' When the pressure .falls to the predetermined amount, the spring 25will again urge the cover of the tank into closed position and preventthe escape ofall the pressure in the tank.

In view of the foregoing, it is seen that the instant invention providesa safety release device for use with spray tanks which precludes thepossibility of an extreme or gradual pressure above a predeterminedamount from being built up within the tank that may cause the tank toblow up and injure the user or a bystander.

' It will be understood that modifications and variations may beetfected without departing from the scope of the novel concepts of thepresent invention, but it is understood that this application is to belimited only by the scope of the appended claims.

We claim as our invention:

1. In a spray tank closed at one end and open at the other end, acentrally open head member secured to the open end of said tank andhaving an inwardly extending radial flange, a cam ring attached to saidflange, a cover assembly including a lid bearing on said flange, asleeve member having a pair of arms removably received by said cam ring,a pressure-movable dome-shaped member positioned between said sleeve andsaid lid, a tensioned spring means located interiorly of said sleevebiasing said dome-shaped member against said lid causing said lid tosealingly engage said flange, and screw means carried by said sleeve foradjusting the tension of said spring means, whereby pressure within saidtank above a predetermined amount breaks the sealing engagement of thelid and flange and allows the excess pressure to escape.

2. In a spray tank closed at one end and open at the other end, acentrally open head member secured to the open end of said tank andhaving an inwardly extending radial flange, a cam ring attached to saidflange, a cover assembly including a lid bearing on said flange, asleeve member having a pair of arms removably received by said cam ring,a dome-shaped member positioned between said sleeve and said lid, atensioned spring means in said sleeve biasing said dome-shaped memberagainst said lid causing said lid to sealingly engage said flange, asealing screw carried by said sleeve for adjusting the tension of saidspring means, said screw having a longitudinal bore therethrough, a handpump mounted on said cover assembly having a plunger rod slidable insaid screw bore, whereby pressure within said tank above a predeterminedamount breaks the sealing engagement of the lid and flange and allowsthe excess pressure to escape.

3. A safety release device for a pressure tank having a flanged openingand a cam ring secured thereto, which comprises a cover bearing againstsaid flanged opening, a sleeve member overlying said cover, a pair ofdiametrically opposed arms integral with said sleeve and removablyengaging said cam ring, a pressure-movable domeshaped member disposedbetween said cover and said sleeve, and a preloaded spring means locatedinteriorly of said sleeve biasing said dome-shaped member against saidcover causing said cover to sealingly engage said flanged opening, andscrew means carried by said sleeve for adjusting the preload of saidspring means.

4. In a spray tank closed at one end and having an opening in the otherend, a retaining ring around said opening, a cover for said opening, apump cylinder carried by said cover to extend into said tank, a coverlocking member engageable with said ring, resilient means carriedinteriorly of said locking member, pressure-movable closure means forthe cylinder in contact with the cover and resilient means to urge saidcover tightly over said opening, and a pump rod extending through saidmember.

5. In a spray tank closed at one end and having an opening in the otherend, a retaining ring around said opening, a cover for said opening, apump cylinder carried by said cover to extend into said tank, a coverlocking member engageable with said ring, resilient means carriedinteriorly of said locking member, pressure-movable closure means forthe cylinder in contact with the cover and resilient means to urge saidcover tightly over said opening, a pump rod extending through saidmember, and locking means on said member for securing the outer end ofsaid pump rod when not in use.

6. In a spray tank closed-at one end and having an opening in the otherend, a retaining ring around said Opening, a cover for said opening, apump cylinder carried by said cover to extend into said tank, a coverlocking member enga-geable with said ring, resilient means carriedinteriorly of said locking member to urge said cover tightly over saidopening, a pressure-movable cap member disposed between said resilientmeans and said cover in contact therewith to function as a closure forsaid cylinder and transfer the spring pressure to said cover, and a pumprod extending through both said members.

7. In a spray tank closed at one end and having an opening in the otherend, a retaining ring around sai-i opening, a cover for said opening, apump cylinder fixedly secured to said cover, a cover locking member inthe form of a sleeve with projecting means to engage said ring, asealing screw in said member having a reduced inner portion, a springaround said portion inside the sleeve, a pressure-movable closuresurrounding said pump cylinder and engaging the spring and cover totransfer spring pressure to said cover, and a pump rod extending throughsaid closure and sealing screw.

8. In a spray tank closed at one end and having an opening in the otherend, a retaining ring around said opening, a cover for said opening, apump cylinder carried by said cover, a cover locking member in the formof a sleeve with projecting means to engage said ring, a sealing screwin said member having a reduced inner portion, a spring around saidportion inside the sleeve, a dome-shaped pressure-movable closure forsaid pump cylinder cngageable at its upper end with the spring and atits lower end with the cover to transfer spring pressure to said cover,and a pump rod extending through said closure and sealing screw, saidsealing screw being adjustable to vary the pressure of said spring onsaid cover, and holding means on the outer end of said screw totemporarily lock the outer end of said pump rod when the pump is not inuse.

References Cited in the file of this patent UNITED STATES PATENTS FriendJune 1, 1954

